It has been a common practice in arcades and similar establishments where pinball machines are operated to award free games or free balls to a player for ringing up a predetermined number of points in a single play for example. In present machines, the awarding of the free games or balls is generally accompanied by the sound of an electronic knocker device within the machine. Unless an operator is present to call attention to the award, however, it may go unnoticed by all but the individual player being awarded.
Pinball machines are provided with various lights, bells and score tabulators, all for the purpose of creating an exciting gameboard situation during each play. By comparison, the signal produced by a knocker for indicating a free game is less noticeable and may be substantially drowned out in a room where other machines are being operated. Various lighting arrangements including a revolving red lamp known as a cherry are utilized in such establishments for creating a general atmosphere of excitement but without means for keying the operation of the lights to the awarding of a replay game by an individual machine. Furthermore, to accomplish such a connection by breaking into the circuit of an existing machine would require the services of one experienced in pinball machine circuitry.